Flexible organic light-emitting display apparatus and method of manufacturing the same

ABSTRACT

In one aspect, a flexible organic light-emitting display apparatus including a substrate; a display device formed on a first surface of the substrate; a thin film encapsulation layer covering the display device; and a protection film generally surrounding the substrate, the display device, and the thin film encapsulation layer, and a method of manufacturing the flexible organic light-emitting display apparatus is provided.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2012-0078958, filed in the Korean IntellectualProperty Office on Jul. 19, 2012, the disclosure of which isincorporated herein by reference in its entirety.

BACKGROUND

Field

The described technology generally relates to a flexible organiclight-emitting display apparatus and a method of manufacturing the same.

Description of the Related Technology

An organic light-emitting display apparatus typically includes anorganic light-emitting diode (OLED) including a hole injectionelectrode, an electron injection electrode, and an organic emissionlayer between the hole and electron injection electrodes, and is aself-emissive display apparatus in which light is emitted while excitonsgenerated when holes injected by the hole injection electrode andelectrons injected by the electron injection electrode are combined inthe organic emission layer transit from an excited state to a groundstate.

As self-emissive display apparatuses, organic light-emitting displayapparatuses may be driven at a low voltage and may have a small weightand thickness since an additional light source is not required, andsince they may have wide viewing angles, high contrast, and fastresponse speeds.

However, since an organic light-emitting display apparatus maydeteriorate due to external moisture or oxygen, an OLED may be sealed toprotect the OLED from external moisture or oxygen.

SUMMARY

The present embodiments provide a flexible organic light-emittingdisplay apparatus, and a method of manufacturing the same.

Some embodiments provide a flexible organic light-emitting displayapparatus including: a substrate; a display device formed on a firstsurface of the substrate; a thin film encapsulation layer covering thedisplay device; and a protection film generally surrounding thesubstrate, the display device, and the thin film encapsulation layer.

In some embodiments, the protection film may include one or morecomponents selected from the group consisting of a silicon (Si)material, an acryl-based resin material, and a urethane-based resinmaterial.

In some embodiments, the silicon (Si) material may include one or morecomponents selected from the group consisting of a silica-basedmaterial, a polysilazane-based material, and a siloxane-based material.

In some embodiments, a maximum thickness of the protection film may be400 μm.

In some embodiments, the protection film generally may surround a firstsurface of the thin film encapsulation layer, side surfaces of the thinfilm encapsulation layer and the substrate, and a second surface of thesubstrate.

In some embodiments, the protection film may include a first protectionfilm that covers a first surface of the thin film encapsulation layerand side surfaces of the thin film encapsulation layer and thesubstrate, and a second protection film that covers a second surface ofthe substrate.

In some embodiments, the second protection film may include a flexiblefilm.

In some embodiments, the thin film encapsulation layer may includeinorganic films and organic films that are alternately stacked.

In some embodiments, the flexible organic light-emitting displayapparatus may further include an optical film disposed on a firstsurface of the protection film.

Some embodiments provide a flexible organic light-emitting displayapparatus including: a flexible substrate; a pixel electrode disposed ona first surface of the flexible substrate; a counter electrode disposedon the pixel electrode; an organic emission layer disposed between thepixel electrode and the counter electrode and emitting light; a thinfilm encapsulation layer disposed on the counter electrode; and aprotection film generally surrounding the flexible substrate, the pixelelectrode, the counter electrode, the organic emission layer, and thethin film encapsulation layer.

In some embodiments, the protection film may include one or morecomponents selected from the group consisting of a silica-basedmaterial, a polysilazane-based material, a siloxane-based material, anacryl-based resin material, and a urethane-based resin material.

In some embodiments, the protection film may generally surround a firstsurface of the thin film encapsulation layer, side surfaces of the thinfilm encapsulation layer and the flexible substrate, and a secondsurface of the flexible substrate.

In some embodiments, the protection film may include a first protectionfilm that covers a first surface of the thin film encapsulation layerand side surfaces of the thin film encapsulation layer and the flexiblesubstrate, and a second protection film that covers a second surface ofthe flexible substrate and includes a material different from the firstprotection film.

Some embodiments provide a method of manufacturing a flexible organiclight-emitting display apparatus, the method including: forming adisplay device on a first surface of a substrate; forming a thin filmencapsulation layer covering the display device; and forming aprotection film that generally surrounds the substrate, the displaydevice, and the thin film encapsulation layer.

In some embodiments, the forming of the protection film may include:forming a coating layer to generally surround the substrate, the displaydevice, and the thin film encapsulation layer, wherein the coating layerincludes a protection film forming curing material; and curing thecoating layer at a temperature below 200° C. and forming the protectionfilm.

In some embodiments, the protection film forming curing material mayinclude one or more components selected from the group consisting of asilica-based material, a polysilazane-based material, a siloxane-basedmaterial, an acryl-based resin material, and a urethane-based resinmaterial.

In some embodiments, the forming of the thin film encapsulation layermay include: forming inorganic films; and forming organic films.

In some embodiments, the forming of the protection film may include:forming a coating layer to generally surround a first surface and sidesurfaces of a stack structure of the substrate, the display device, andthe thin film encapsulation layer, wherein the coating layer includes aprotection film forming curing material; curing the coating layer at atemperature below 200° C. and forming a first protection film; andattaching a flexible film to cover a second surface of the stackstructure and forming a second protection film.

In some embodiments, the method may further include: forming an opticalfilm directly on the protection film.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present embodimentswill become more apparent by describing in detail exemplary embodimentsthereof with reference to the attached drawings in which:

FIG. 1 is a schematic cross-sectional view of a flexible organiclight-emitting display apparatus according to an aspect of the presentembodiments;

FIG. 2 is a detailed cross-sectional view of the flexible organiclight-emitting display apparatus of FIG. 1;

FIG. 3 is a schematic cross-sectional view of one pixel region of theflexible organic light-emitting display apparatus of FIG. 2;

FIGS. 4 through 7 are sequential cross-sectional views for describing amethod of manufacturing the flexible organic light-emitting displayapparatus of FIG. 1, according to an aspect of the present embodiments;

FIG. 8 is a schematic cross-sectional view of a flexible organiclight-emitting display apparatus according to an aspect of the presentembodiments; and

FIG. 9 is a detailed cross-sectional view of the flexible organiclight-emitting display apparatus of FIG. 8.

DETAILED DESCRIPTION

Hereinafter, the present disclosure will be described in detail byexplaining exemplary embodiments with reference to the attacheddrawings. The invention may, however, be embodied in many differentforms and should not be construed as being limited to the embodimentsset forth herein. Meanwhile, the terminology used herein is for thepurpose of describing particular embodiments and is not intended tolimit the invention. As used herein, the singular forms are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof. Also, it will be understood that,although the terms ‘first’, ‘second’, etc. may be used herein todescribe various elements, these elements should not be limited by theseterms. These terms are only used to distinguish one element fromanother.

In the drawings, lengths and sizes of layers and regions may beexaggerated for clarity. It will be understood that when an element orlayer is referred to as being “on” another element or layer, the elementor layer can be directly on another element or layer or interveningelements or layers. In contrast, when an element is referred to as being“directly on” another element or layer, there are no interveningelements or layers present.

As used herein, the term “and/or” includes any and all combinations ofone or more of the associated listed items. Expressions such as “atleast one of,” when preceding a list of elements, modify the entire listof elements and do not modify the individual elements of the list.

As used herein, the term “generally surrounds” or “generallysurrounding” refers an item covering all exposed surfaces of the listeditems. For example, embodiments that state a protection film generallysurrounds a substrate, a display device, and a thin film encapsulationlayer provides that the protection film covers all the exposed surfacesof the substrate, the display device, and the thin film encapsulationlayer.

FIG. 1 is a schematic cross-sectional view of a flexible organiclight-emitting display apparatus 100 according to an embodiment. FIG. 2is a detailed cross-sectional view of the flexible organiclight-emitting display apparatus 100 of FIG. 1. FIG. 3 is a schematiccross-sectional view of one pixel region of the flexible organiclight-emitting display apparatus 100 of FIG. 2.

Referring to FIGS. 1 and 2, the flexible organic light-emitting displayapparatus 100 (hereinafter referred to as an “organic light-emittingdisplay apparatus”) according to an embodiment of the present inventionmay include a substrate 110, a display device 120 disposed on a firstsurface 111 of the substrate 110, a thin film encapsulation layer 150disposed on the display device 120, and a protection film 160. Theprotection film 160 may be formed to generally surround the substrate110, the display device 120, and the thin film encapsulation layer 150.

Referring to FIGS. 2 and 3, the display device 120 may include anorganic light-emitting diode (OLED) 140 including a pixel electrode 141disposed on the substrate 110, a counter electrode 143 disposed on thepixel electrode 141, and an organic emission layer 142 disposed betweenthe pixel electrode 141 and the counter electrode 143. In someembodiments, the OLED 140 emits red, green, and blue light according tocurrent and displays predetermined image information. In someembodiments, the OLED 140 may be disposed on a device/wiring layer 130.

In some embodiments, the substrate 110 may be a flexible substrate andmay include polymer having excellent heat resistance and durability. Forexample, the substrate 110 may include any one selected from the groupconsisting of polyethersulfone (PES), polyarylate (PAR), polyetherimide(PEI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET),polyphenylene sulfide (PPS), polyallylate, polyimide (PI), polycarbonate(PC), cellulose triacetate, cellulose acetate propionate (CAP),poly(arylene ether sulfone), and a combination thereof.

In some embodiments, the device/wiring layer 130 may be disposed on thefirst surface 111 of the substrate 110 and may include a driving thinfilm transistor (TFT) for driving the OLED 140, a switching thin filmtransistor (not shown), a capacitor, and wirings (not shown) connectedto the driving TFT and the capacitor. The driving TFT includes an activelayer 131, a gate electrode 133, and source and drain electrodes 135 aand 135 b.

Although not shown, a barrier layer for preventing penetration ofexternal impurities such as moisture or oxygen into the OLED 140 throughthe substrate 110 may be further disposed between the substrate 110 andthe device/wiring layer 130.

The OLED 140 is disposed on the device/wiring layer 130. The OLED 140includes the pixel electrode 141, the organic emission layer 142disposed on the pixel electrode 141, and the counter electrode 143formed on the organic emission layer 142.

In some embodiments, the pixel electrode 141 may be an anode and thecounter electrode 143 may be a cathode. However, the present embodimentsare not limited thereto and, according to a driving method of theorganic light-emitting display apparatus 100, the pixel electrode 141may be a cathode and the counter electrode 143 may be an anode. Holesand electrons are injected from the pixel electrode 141 and the counterelectrode 143, respectively, into the organic emission layer 142. Lightis emitted while excitons formed when the injected holes and electronsare combined transit from an excited state to a ground state.

The pixel electrode 141 is electrically connected to the driving TFT ofthe device/wiring layer 130.

Although the OLED 140 is disposed on the device/wiring layer 130including the driving TFT in the present embodiment, the presentinvention is not limited thereto and various modifications may be made.For example, the pixel electrode 141 of the OLED 140 may be formed atthe same level as the active layer 131, the gate electrode 133, or thesource and drain electrodes 135 a and 135 b of the driving TFT.

Furthermore, although the gate electrode 133 of the driving TFT isdepicted as disposed above the active layer 131 the present embodimentsis not limited thereto and the gate electrode 133 may also be disposedunder the active layer 131.

In some embodiments, the pixel electrode 141 of the OLED 140 may be areflective electrode and may include a reflective film formed of silver(Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold(Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), or acompound thereof, and a transparent or translucent electrode layerformed on the reflective film.

In some embodiments, the transparent or translucent electrode layer mayinclude at least one selected from the group consisting of indium tinoxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide(In₂O₃), indium gallium oxide (IGO), and aluminum zinc oxide (AZO).

In some embodiments, the counter electrode 143 disposed to face thepixel electrode 141 may be a transparent or translucent electrode, andmay be formed as a metallic thin film including lithium (Li), calcium(Ca), lithium fluoride/calcium (LiF/Ca), lithium fluoride/aluminum(LiF/Al), aluminum (Al), silver (Ag), magnesium (Mg), or a compoundthereof, and having a low work function. Also, an auxiliary electrodelayer or a bus electrode may be further formed on the metallic thin filmby using a material for forming a transparent electrode, e.g., ITO, IZO,ZnO, or In₂O₃.

Accordingly, the counter electrode 143 may transmit the light emittedfrom the organic emission layer 142.

Although the depicted embodiments describe a case where light emittedfrom the OLED 140 is emitted toward a top surface, i.e., the firstsurface 111 of the substrate 110 (a top emission type), the presentembodiments are not limited thereto. In some embodiments, the light maybe emitted toward a second surface 112 of the substrate 110 (a bottomemission type), and the light may be emitted toward the first and secondsurfaces 111 and 112 of the substrate 110 (a dual emission type). In thecase where the organic light-emitting display apparatus 100 according toan embodiment of the present invention is a bottom emission type displayapparatus, the pixel electrode 141 may be formed as a semi-transmissionfilm, and the counter electrode 143 may be formed as a reflective film.In some embodiments, where the organic light-emitting display apparatus100 is a dual emission type display apparatus, the pixel electrode 141and the counter electrode 143 may be formed as transparent ortranslucent films.

In some embodiments, the organic emission layer 142 may be disposedbetween the pixel electrode 141 and the counter electrode 143, and maybe formed of a low-molecular or high-molecular organic material.

In addition to the organic emission layer 142, intermediate layers suchas a hole transport layer (HTL), a hole injection layer (HIL), anelectron transport layer (ETL), and an electron injection layer (EIL)may be selectively disposed between the pixel electrode 141 and thecounter electrode 143.

In some embodiments, the thin film encapsulation layer 150 may seal andprotect the OLED 140 from the outside. In some embodiments, the thinfilm encapsulation layer 150 may include a thin film including one ormore inorganic films 151 and one or more organic films 152. In someembodiments, the substrate 110 may be the flexible substrate, and thethin film encapsulation layer 150 may be formed as the thin filmincluding the inorganic films 151 and the organic films 152, therebyeasily implementing flexibility and thinning of the organiclight-emitting display apparatus 100.

In some embodiments, the inorganic films 151 may be disposed closest tothe OLED 140 and include a metal oxide, a metal nitride, a metalcarbide, or a compound thereof. For example, the inorganic films 151 mayinclude at least one inorganic material from Al₂O₃, TiO₂, ZrO, SiO₂,AlON, AlN, SiON, Si₃N₄, ZnO, and Ta₂O₅.

In some embodiments, the organic films 152 may include polymer basedmaterials. In some embodiments, the polymer based materials may includeacryl based resin, epoxy based resin, polyimide, polyethylene, etc. Insome embodiments, the organic films 152 may reduce internal stress of,complement defects of, and planarize the inorganic films 510.

Although the depicted embodiments exemplify a case where the inorganicfilms 151 are stacked three times, and the organic films 152 are stackedtwo times, the present embodiments are not limited thereto. That is, thenumber of inorganic films 151 and organic films 152 that are alternatelystacked is not limited by the depicted embodiments.

In some embodiments, the protection film 160 may be formed to generallysurround the substrate 110, the display device 120, and the thin filmencapsulation layer 150 while covering a first surface 155 of the thinfilm encapsulation layer 150, side surfaces 113 and 153 of the thin filmencapsulation layer 150 and the substrate 110, and the second surface112 of the substrate 110. In some embodiments, the protection film 160may be formed to generally surround the substrate 110, the displaydevice 120, and the thin film encapsulation layer 150, therebypreventing a thin film encapsulation from being separated from theorganic light-emitting display apparatus 100 during a process ofmanufacturing the organic light-emitting display apparatus 100.

A comparative example of the present embodiments, where the protectionfilm 160 is not formed in the organic light-emitting display apparatus100, after the thin film encapsulation layer 150 is formed, a film maybe temporarily attached so as to prevent the thin film encapsulationlayer 150 from being damaged during a process of attaching an opticalfilm 180 on the thin film encapsulation layer 150. The temporarilyattached film is removed before the optical film 180 is attached to thethin film encapsulation layer 150. In this regard, an adhesive force ofthe temporarily attached film may cause a peel-off phenomenon in thatthe thin film encapsulation layer 150 that is thin peels off from thesubstrate 110 and/or the display device 120 or a fine cracktherebetween. In the case where the thin film encapsulation layer 150peels off from the substrate 110 and/or the display device 120 or thefine crack therebetween, moisture or oxygen may penetrate into theorganic emission layer 142. Also, an electrostatic force that occurswhen the temporarily attached film is removed may deteriorate or damagea characteristic of the display device 120.

In contrast, according to the present embodiments, the protection film160 may be formed to generally surround the substrate 110, the displaydevice 120, and the thin film encapsulation layer 150, and thus no filmis temporarily attached in order to protect the thin film encapsulationlayer 150 during the process of manufacturing the organic light-emittingdisplay apparatus 100.

In addition, the protection film 160 may be formed to generally surroundthe substrate 110, the display device 120, and the thin filmencapsulation layer 150, and thus a path via which oxygen or moisturemay penetrate may be totally blocked.

In some embodiments, the protection film 160 may be formed using acoating and curing method. In some embodiments, the protection film 160may include one of a silicon (Si) material, an acryl-based resinmaterial, and a urethane-based resin material. In some embodiments, thesilicon (Si) material may include a silica-based material, apolysilazane-based material, and a siloxane-based material.

In some embodiments, the thickness of the protection film 160 may beformed to the extent that the flexibility of the organic light-emittingdisplay apparatus 100 is not damaged. For example, the thickness of theprotection film 160 may be less than about 400 μm such that flexibilityof the organic light-emitting display apparatus 100 may be secured.

In some embodiments, the optical film 180 may be further formed on afirst surface 161 of the protection film 160. In some embodiments, theoptical film 180 may use a phase delay plate and/or a polarizationplate. In some embodiments, the optical film 180 may inhibit reflectionof external light to enhance visibility and contrast of the organiclight-emitting display apparatus 100.

A method of manufacturing the organic light-emitting display apparatus100 will now be described.

FIGS. 4 through 7 are sequential cross-sectional views for describing amethod of manufacturing the organic light-emitting display apparatus 100of FIG. 1, according to an embodiment.

Referring to FIG. 4, the display device 120, including the device/wiringlayer 130 and the OLED 400, including the pixel electrode 141, theorganic emission layer 142, and the counter electrode 143, are formed onthe first surface 111 of the substrate 110.

In some embodiments, the substrate 110 may be a flexible substrate andmay be a plastic substrate including polymer having excellent heatresistance and durability as described above. In some embodiments, theflexible substrate may be disposed on a support substrate (not shown)formed of glass for supporting the flexible substrate. In someembodiments, the support substrate (not shown) may be removed after aprocess completely ends or during the process.

In some embodiments, a barrier layer (not shown) may be further formedon the first surface 111 of the substrate 110. In some embodiments, thebarrier layer (not shown) may include the inorganic films 151 and/or theorganic films 152, and prevents penetration of external impurities intothe device/wiring layer 130 and the OLED 140 through the substrate 110.

In some embodiments, the device/wiring layer 130 may include the drivingTFT (see FIG. 3) for driving the OLED 140, a capacitor (not shown), andwiring (not shown).

In some embodiments, the pixel electrode 141, the organic emission layer142, and the counter electrode 143 are sequentially formed on thedevice/wiring layer 130.

In some embodiments, the pixel electrode 141 may be a reflectiveelectrode, and the counter electrode 143 may be a transparent ortranslucent electrode. Accordingly, light generated by the organicemission layer 142 may be emitted toward the counter electrode 143directly or after being reflected on the pixel electrode 141. In thisregard, the counter electrode 143 may be formed as a translucentelectrode and thus the pixel electrode 141 and the counter electrode 143may form a resonance structure.

In some embodiments, the organic light-emitting display apparatus 100may be formed having a top emission type structure as described above.According to another embodiment, the organic light-emitting displayapparatus 100 may be formed as a bottom emission type or a dual emissiontype structure. In this case, the pixel electrode 141 and the counterelectrode 143 are the same as described above.

In some embodiments, the organic emission layer 142 may be formed of alow-molecular or high-molecular organic material. In addition to theorganic emission layer 142, the intermediate layers as stated above maybe selectively formed between the pixel electrode 141 and the counterelectrode 143. Although the OLED 140 is formed on the device/wiringlayer 130 in the depicted embodiment, the present embodiments are notlimited thereto and the device/wiring layer 130 and the OLED 140 may beformed at the same level.

Referring to FIG. 5, the thin film encapsulation layer 150 is formed. Insome embodiments, the thin film encapsulation layer 150 may be formed byalternately forming the inorganic films 151 and the organic films 152.In some embodiments, the inorganic films 151 may be formed as thelowermost and uppermost layers of the thin film encapsulation layer 150contacting the counter electrode 143. In some embodiments, the number ofinorganic films 151 and organic films 152 that are alternately formed isnot limited to the number shown in FIG. 5.

Thereafter, referring to FIG. 6, a protection film forming curingmaterial C is applied to generally surround the substrate 110, thedisplay device 120, and the thin film encapsulation layer 150. Morespecifically, the protection film forming curing material C may becoated to cover the first surface 155 of the thin film encapsulationlayer 150, the side surfaces 113 and 153 of the thin film encapsulationlayer 150 and the substrate 110, and the second surface 112 of thesubstrate 110. In this regard, the protection film forming curingmaterial C may be coated having a thickness of less than about 400 μm.In some embodiments, the protection film forming curing material C maybe coated having a thickness of less than 400 μm. In some embodiments,the protection film forming curing material C may be coated having athickness in a range of from 100 μm to 400 μm.

In some embodiments, the protection film forming curing material C mayinclude one of a silicon (Si) material, an acryl-based resin material,and a urethane-based resin material. In some embodiments, the silicon(Si) material may include a silica-based material, a polysilazane-basedmaterial, and a siloxane-based material. In some embodiments, theprotection film forming curing material C may be coated using a spraycoating method, a spin coating method, a slit coating method, etc. Insome embodiments, a roller coating method may be used to coat theprotection film forming curing material C.

Referring to FIG. 7, the protection film 160 may be formed by curing theprotection film forming curing material C by using thermal energy orlight energy such as UV light. A curing temperature may be below about200° C. In some embodiments, a curing temperature may be below 200° C.In some embodiments, a curing temperature may be in a range of from 100°C. to 200° C. If the curing temperature exceeds 200° C., an organiclight-emitting material of the organic emission layer 142 maydeteriorate due to a high temperature.

In some embodiments, the protection film forming curing material C mayfurther include an additive so that the protection film forming curingmaterial C may be cured at the temperature below about 200° C. Theadditive may include palladium, an amine-based material, etc. but is notlimited thereto.

In some embodiments, the optical film 180 may be further attached to thefirst surface 161 of the protection film 160. A process of removingimpurities that are likely to be present in the first surface 161 of theprotection film 160 may be further performed before the optical film 180is attached. In some embodiments, the optical film 180 may use a phasedelay plate or a polarization plate.

In the case of the organic light-emitting display apparatus according tothe comparison example as described above, a film is temporarilyattached so as to prevent the thin film encapsulation layer 150 frombeing damaged during a process of attaching the optical film 180 ontothe thin film encapsulation layer 150, whereas, according to the presentembodiments, the protection film 160 may be formed to generally surroundthe substrate 110, the display device 120, and the thin filmencapsulation layer 150, and thus no film is temporarily attached inorder to protect the thin film encapsulation layer 150 during theprocess of manufacturing the organic light-emitting display apparatus100 as described above. In addition, the protection film 160 may beformed to generally surround the substrate 110, the display device 120,and the thin film encapsulation layer 150, and thus a path via whichoxygen or moisture may penetrate may be totally blocked.

FIG. 8 is a schematic cross-sectional view of a flexible organiclight-emitting display apparatus 200 according to another depictedembodiment of the present embodiments. FIG. 9 is a detailedcross-sectional view of the flexible organic light-emitting displayapparatus 200 of FIG. 8.

Referring to FIGS. 8 and 9, the flexible organic light-emitting displayapparatus 200 may include the substrate 110, the display device 120disposed on the first surface 111 of the substrate 110, the thin filmencapsulation layer 150 disposed on the display device 120, andprotection films 260 and 270. In some embodiments, the protection films260 and 270 may be formed to generally surround the substrate 110, thedisplay device 120, and the thin film encapsulation layer 150. In someembodiments, the optical film 180 may be further disposed on theprotection films 260 and 270, for example, directly on the protectionfilms 260 and 270.

In some embodiments, the display device 120 may include the OLED 140including the pixel electrode 141 disposed on the substrate 110, thecounter electrode 143 disposed on the pixel electrode 141, and theorganic emission layer 142 disposed between the pixel electrode 141 andthe counter electrode 143. In some embodiments, the OLED 140 emits red,green, and blue light according to current and displays predeterminedimage information, and may be disposed on the device/wiring layer 130,which is the same as described with reference to FIGS. 1 through 7.

However, the organic light-emitting display apparatus 100 and theflexible organic light-emitting display apparatus 200 differ from eachother in that the protection film 160 described with reference to FIGS.1 through 7 has a structure in which one material surrounds thesubstrate 110, the display device 120, and the thin film encapsulationlayer 150, whereas the protection films 260 and 270 according to theembodiment depicted in FIGS. 8 and 9 may include two differentmaterials.

Differences between the organic light-emitting display apparatus 100 andthe flexible organic light-emitting display apparatus 200 will now bedescribed.

The protection films 260 and 270 may surround the substrate 110, thedisplay device 120, and the thin film encapsulation layer 150 andinclude the first protection film 260 formed to cover the first surface155 of the thin film encapsulation layer 150 and the side surfaces 113and 153 of the thin film encapsulation layer 150 and the substrate 110,and the second protection film 270 formed to cover the second surface112 of the substrate 110.

The first protection film 260 may be formed of the same material as theprotection film 160 described with reference to FIG. 1. For example, thefirst protection film 260 may include one or more components selectedfrom the group consisting of a silicon (Si) material such as asilica-based material, a polysilazane-based material, or asiloxane-based material, an acryl-based resin material, and aurethane-based resin material.

As described above, the first protection film 260 may be formed byapplying the protection film forming curing material C using a spraycoating method and curing the protection film forming curing material Cat a temperature below about 200° C. by using thermal energy or lightenergy such as UV light. In some embodiments, a curing temperature maybe below 200° C. In some embodiments, a curing temperature may be in arange of from 100° C. to 200° C. In some embodiments, the protectionfilm forming curing material C for forming the first protection film 260may be applied on the first surface 155 of the thin film encapsulationlayer 150 and the side surfaces 113 and 153 of the thin filmencapsulation layer 150 and the substrate 110, respectively.

In some embodiments, the second protection film 270 may include aflexible film. In some embodiments, the flexible film may be attachedonto the second surface 112 of the substrate 110 that is externallyexposed after the first protection film 260 is formed by curing theprotection film forming curing material C.

With respect to the protection films 260 and 270, the flexible organiclight-emitting display apparatus 200 may include, in some embodiments,the first protection film 260, a temporary film is not used when theoptical film 180 is attached, thereby preventing the thin filmencapsulation layer 150 from being peeled off or a fine crack fromoccurring between the thin film encapsulation layer 150 and thesubstrate 110, and preventing a device from deteriorating or beingdamaged due to static electricity.

In some embodiments, an organic light-emitting material may be protectedfrom oxygen or moisture, a manufacturing process may be simplified, andan additional film may not be temporarily attached during themanufacturing process, thereby preventing a device from deteriorating orbeing damaged due to the temporarily attached film.

While the present embodiments have been particularly shown and describedwith reference to exemplary embodiments thereof, it will be understoodby those of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the embodiments defined by the following claims.

What is claimed is:
 1. A flexible organic light-emitting displayapparatus comprising: a substrate including a first surface and a secondsurface opposite the first surface; a display device on the firstsurface of the substrate and comprising a plurality of organiclight-emitting diodes (OLEDs); a thin film encapsulation layer includingat least an organic film and at least an inorganic film and covering thedisplay device, an end portion of the thin film encapsulation layerextends beyond an end of the display device and partially covers an areaof the first surface of the substrate on which the display device is notdisposed; a first protection film arranged to directly contact the thinfilm encapsulation layer and generally covering each exposed surface ofthe substrate and the thin film encapsulation layer; and a secondprotection film on the second surface of the substrate.
 2. The flexibleorganic light-emitting display apparatus of claim 1, wherein the firstprotection film comprises one or more components selected from the groupconsisting of a silicon (Si) material, an acryl-based resin material,and a urethane-based resin material.
 3. The flexible organiclight-emitting display apparatus of claim 2, wherein the firstprotection film comprises one or more components consisting of a silicon(Si) material, the silicon (Si) material comprises a silica-basedmaterial, a polysilazane-based material, and a siloxane-based material.4. The flexible organic light-emitting display apparatus of claim 1,wherein a maximum thickness of the first protection film is 400 μm. 5.The flexible organic light-emitting display apparatus of claim 1,wherein the first protection film covers a first surface of the thinfilm encapsulation layer and side surfaces of the thin filmencapsulation layer and the substrate, and the second protection filmcovers the second surface of the substrate.
 6. The flexible organiclight-emitting display apparatus of claim 5, wherein each of the firstand second protection films comprises a flexible film.
 7. The flexibleorganic light-emitting display apparatus of claim 1, wherein the thinfilm encapsulation layer comprises inorganic films and organic filmsthat are alternately stacked.
 8. The flexible organic light-emittingdisplay apparatus of claim 1, further comprising an optical filmdisposed on a first surface of the first protection film.
 9. A flexibleorganic light-emitting display apparatus comprising: a flexiblesubstrate including a first surface and a second surface opposite thefirst surface; a pixel electrode disposed on the first surface of theflexible substrate; a counter electrode disposed on the pixel electrode;an organic emission layer disposed between the pixel electrode and thecounter electrode and emitting light; a thin film encapsulation layerdisposed on the counter electrode and including at least an organic filmand at least an inorganic film, an end portion of the thin filmencapsulation layer extends beyond an end of the counter electrode andpartially covers an area of the substrate on which the counter electrodeis not disposed; a first protection film arranged to directly contactthe thin film encapsulation layer and generally covering each exposedsurface of the flexible substrate-and the thin film encapsulation layer;and a second protection film on the second surface of the substrate. 10.The flexible organic light-emitting display apparatus of claim 9,wherein the first protection film comprises one or more componentsselected from the group consisting of a silica-based material, apolysilazane-based material, a siloxane-based material, an acryl-basedresin material, and a urethane-based resin material.
 11. The flexibleorganic light-emitting display apparatus of claim 9, wherein the firstprotection film covers a first surface of the thin film encapsulationlayer and side surfaces of the thin film encapsulation layer and theflexible substrate, and the second protection film covers the secondsurface of the flexible substrate and comprises a material differentfrom the first protection film.